Image processing apparatus including a correction circuit configured to stop formation of an inclination-corrected line in a main scanning direction, image forming apparatus, image processing method and non-transitory computer readable medium

Abstract

An image processing apparatus includes a memory, a correction circuit, and a calculation circuit. The memory stores image data of an original image that is moved in a sub-scanning direction with respect to an image sensor. The correction circuit sequentially reads the image data from the memory line by line in the main scanning direction, extracts a pixel in a position corresponding to the inclination, and forms an inclination-corrected line in the main scanning direction to correct the inclination. The calculation circuit calculates an amount of movement of a corner of the original image with respect to the sub-scanning direction before and after correction of inclination of the original image with respect to a main scanning direction. The correction circuit restricts progress of formation of the inclination-corrected line based on the amount of movement. The amount of movement is applied when the inclination of the original image is corrected.

What is claimed is: 
     
       1. An image processing apparatus comprising:
 a memory to store image data of an original image moved in a sub-scanning direction with respect to an image sensor that scans the original image in a main scanning direction to generate the image data; 
 a correction circuit to sequentially read the image data from the memory line by line in the main scanning direction, extract a pixel in a position corresponding to an inclination of the original image with respect to the main scanning direction, and form an inclination-corrected line in the main scanning direction to correct the inclination of the original image; and 
 a calculation circuit to calculate an amount of movement of a corner of the original image with respect to the sub-scanning direction before and after correction of the inclination of the original image with respect to the main scanning direction by the correction circuit, the amount of movement being applied when the inclination of the original image is corrected, 
 the correction circuit being configured to stop formation of the inclination-corrected line in the main scanning direction upon a difference between a position in the sub-scanning direction, when the image data is sequentially read line by line in the main scanning direction, and a position in the sub-scanning direction, when the inclination-corrected line in the main scanning direction is formed, is relatively smaller than the amount of movement. 
 
     
     
       2. The image processing apparatus according to  claim 1 , wherein the correction circuit forms the inclination-corrected line in the main scanning direction at a cycle shorter than a cycle in which the correction circuit sequentially reads the image data line by line in the main scanning direction. 
     
     
       3. The image processing apparatus according to  claim 1 , wherein the calculation circuit calculates the inclination of the original image with respect to the main scanning direction based on the image data. 
     
     
       4. The image processing apparatus according to  claim 1 , wherein the calculation circuit is configured to calculate an amount of movement of a left corner of the original image with respect to the sub-scanning direction, before and after the correction of the inclination, upon the image data being rotated clockwise to correct the inclination, and is configured to calculate an amount of movement of a right corner of the original image with respect to the sub-scanning direction, before and after the correction of the inclination, upon, the image data being rotated counterclockwise to correct the inclination. 
     
     
       5. An image forming apparatus comprising the image processing apparatus according to  claim 1  to output the image data after the correction of the inclination. 
     
     
       6. The image processing apparatus according to  claim 1 , wherein the correction circuit is configured to restrict progress of formation of the inclination-corrected line in the main scanning direction based on the amount of movement. 
     
     
       7. An image processing method comprising:
 storing image data of an original image moved in a sub-scanning direction with respect to an image sensor that scans the original image in a main scanning direction to generate the image data; 
 correcting an inclination of the original image with respect to the main scanning direction, 
 the correcting including:
 sequentially reading the image data from a memory line by line in the main scanning direction; 
 extracting a pixel in a position corresponding to the inclination; and 
 forming an inclination-corrected line in the main scanning direction; and 
 
 calculating an amount of movement of a corner of the original image with respect to the sub-scanning direction before and after the correcting of the inclination of the original image with respect to the main scanning direction, the amount of movement being applied when the inclination of the original image is corrected, 
 the correcting stopping formation of the inclination-corrected line in the main scanning direction upon a difference between a position in the sub-scanning direction, when the image data is sequentially read line by line in the main scanning direction, and a position in the sub-scanning direction, when the inclination-corrected line in the main scanning direction is formed, is relatively smaller than the amount of movement. 
 
     
     
       8. The image processing method according to  claim 7 , wherein the correcting includes restricting progress of formation of the inclination-corrected line in the main scanning direction based on the amount of movement. 
     
     
       9. The image processing method according to  claim 7 , wherein the correcting includes forming the inclination-corrected line in the main scanning direction at a cycle shorter than a cycle in which the image data is sequentially read line by line in the main scanning direction. 
     
     
       10. The image processing method according to  claim 7 , wherein the calculating includes calculating the inclination of the original image with respect to the main scanning direction based on the image data. 
     
     
       11. The image processing method according to  claim 7 , wherein the calculating includes calculating an amount of movement of a left corner of the original image with respect to the sub-scanning direction, before and after correction of the inclination, upon the image data being rotated clockwise to correct the inclination, and includes calculating an amount of movement of a right corner of the original image with respect to the sub-scanning direction, before and after the correction of the inclination, upon the image data is being rotated counterclockwise to correct the inclination. 
     
     
       12. A non-transitory recording medium storing image processing program code that causes a computer to execute an image processing method, the method comprising:
 storing image data of an original image moved in a sub-scanning direction with respect to an image sensor that scans the original image in a main scanning direction to generate the image data; 
 correcting an inclination of the original image with respect to the main scanning direction, 
 the correcting including:
 sequentially reading the image data from a memory line by line in the main scanning direction; 
 extracting a pixel in a position corresponding to the inclination; and 
 forming an inclination-corrected line in the main scanning direction; and 
 
 calculating an amount of movement of a corner of the original image with respect to the sub-scanning direction before and after the correcting of the inclination of the original image with respect to the main scanning direction, the amount of movement being applied when the inclination of the original image is corrected 
 the correcting stopping formation of the inclination-corrected line in the main scanning direction upon a difference between a position in the sub-scanning direction, when the image data is sequentially read line by line in the main scanning direction, and a position in the sub-scanning direction, when the inclination-corrected line in the main scanning direction is formed, is relatively smaller than the amount of movement. 
 
     
     
       13. The non-transitory recording medium according to  claim 12 , wherein the correcting includes restricting progress of formation of the inclination-corrected line in the main scanning direction based on the amount of movement. 
     
     
       14. The non-transitory recording medium according to  claim 12 , wherein the correcting includes forming the inclination-corrected line in the main scanning direction at a cycle shorter than a cycle in which the image data is sequentially read line by line in the main scanning direction. 
     
     
       15. The non-transitory recording medium according to  claim 12 , wherein the calculating includes calculating the inclination of the original image with respect to the main scanning direction based on the image data. 
     
     
       16. The non-transitory recording medium according to  claim 12 , wherein the calculating includes calculating an amount of movement of a left corner of the original image with respect to the sub-scanning direction, before and after correction of the inclination, upon the image data being rotated clockwise to correct the inclination, and includes calculating an amount of movement of a right corner of the original image with respect to the sub-scanning direction, before and after the correction of the inclination, upon the image data is being rotated counterclockwise to correct the inclination.